802.11ax Packet Formats ========================== .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is the packet format in IEEE 802.11ax?** It defines the structure of MAC and PHY frames optimized for high efficiency and multi-user operation. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does 802.11ax packet format differ from 802.11ac?** It introduces new fields for OFDMA, MU-MIMO, and Target Wake Time scheduling while maintaining backward compatibility. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What are the main components of an 802.11ax MAC frame?** Frame Control, Duration/ID, Address fields, Sequence Control, QoS Control, HT Control, and Frame Body. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is the significance of the HE (High Efficiency) Control field?** It carries control information related to new 802.11ax features like resource unit allocation and spatial reuse. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How is OFDMA reflected in the packet format?** OFDMA uses special trigger frames and control fields to indicate resource unit assignments for simultaneous transmissions. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is the PPDU format in 802.11ax?** It includes a Legacy preamble, HE-LTF fields, HE-SIG-A and HE-SIG-B fields, followed by data symbols. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What role do the HE-SIG fields play?** HE-SIG-A and HE-SIG-B convey control information such as MCS, RU allocation, and transmission parameters. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does 802.11ax support multiple spatial streams in the packet?** Packet format includes fields for MU-MIMO operation with spatial stream assignments and beamforming info. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Are there new frame types introduced in 802.11ax?** Yes, new control frames like Trigger Frames and Multi-User Block ACK frames support multi-user coordination. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is a Trigger Frame?** A special control frame sent by the AP to schedule uplink transmissions from multiple stations simultaneously. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does 802.11ax handle fragmentation in packet formats?** Similar to previous standards, fragmentation fields allow splitting large frames into smaller subframes. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11ax support Quality of Service (QoS) in packet formats?** Yes, the QoS Control field is enhanced to support differentiated traffic handling. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is the maximum size of an 802.11ax MAC frame?** Up to 7935 bytes, larger than previous standards to accommodate increased data and control info. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How are legacy devices supported in 802.11ax packet formats?** The Legacy preamble and fields ensure backward compatibility with older 802.11 devices. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is the role of the PHY preamble in 802.11ax?** It enables synchronization, channel estimation, and signaling of packet format and rate. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does 802.11ax handle encryption in packet formats?** Encryption headers and trailers are included per standard MAC layer security protocols like WPA3. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Are control frames shorter than data frames in 802.11ax?** Yes, control frames have minimal headers and fixed lengths for fast processing. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does 802.11ax support target wake time (TWT) in packet formats?** TWT information is carried in specific management frames for scheduling device wake/sleep cycles. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Where can I find detailed 802.11ax packet format specifications?** In the IEEE 802.11ax standard document and related technical references from the Wi-Fi Alliance. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow Topics in this section, * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`packet_formats Basic Setup on Ubuntu using IPv4 ` * :ref:`Reference links ` .. _packet_formats_step1: .. tab-set:: .. tab-item:: Learnings in this section * In this section, you are going to learn .. _packet_formats_step2: .. tab-set:: .. tab-item:: Terminology * Terminology .. _packet_formats_step3: .. tab-set:: .. tab-item:: Version Info * Version Info .. _packet_formats_step18: .. tab-set:: .. tab-item:: packet_formats Basic Setup on Ubuntu using IPv4 * setup .. _packet_formats_step17: .. tab-set:: .. tab-item:: Reference links * Reference links